The instant invention relates to a process for piecing an open-end spinning device in which a yarn is fed back from a cross-wound package a first time, is then re-wound on a predetermined generating line of the cross-wound package in the form of parallel windings and is finally fed back from these parallel windings for a second time to an open-end spinning element. It is then cut to a predetermined length and the cut yarn is back-fed to combine with the newly fed fibers and is finally continuously drawn off in form of a yarn with incorporated fibers, as well as a device to carry out this process.
In a known process the yarn is stored by means of the suction pipe which sucks the yarn away from the cross-wound package, and from this store it is again wound up on the cross-wound package while parallel windings are formed (U.S. Pat. No. 4,494,371). In such a swivelling suction pipe which has, furthermore, the task of presenting the yarn to a transfer element for transfer to the spinning element, the yarn must, however, be deflected several times, and this makes it more difficult to draw the yarn off again to constitute parallel windings on the cross-wound package. In addition the yarn's surface is affected as it is pulled over deflection points. By retaining the yarn end in the suction pipe during re-winding of the yarn to constitute parallel windings on the cross-wound package, the yarn is stretched to varying degrees, depending on the material and yarn thickness, due to the yarn tension which then occurs, leading to imprecision in yarn length. In addition the increased yarn tension leads to constrictions on the package which cause problems in the process. These process problems occur during back-feeding for piecing as well as in the further processing of the yarn, as the yarn length wound up in form of parallel windings exceeds the yarn length needed for piecing for reasons of security, so that a short yarn length of yarn, representing a remainder of the parallel windings, remains on the cross-wound package after piecing.